


Stronger than any Spell

by Stacysmash



Series: Harry Potter AU [6]
Category: Haikyuu!!
Genre: Alternate Universe - Harry Potter Setting, Body Swap, Dueling, Established Relationship, Fluff, Harry Potter AU, Light Sexual Content, M/M, Sequel, So Sappy, kurodai week 2018 Day 1: Body Swap
Language: English
Status: Completed
Published: 2018-05-06
Updated: 2018-05-06
Packaged: 2019-05-03 00:28:39
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,508
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14556918
Author URL: https://archiveofourown.org/users/Stacysmash/pseuds/Stacysmash
Summary: Hogwarts is holding their yearling dueling club for the second years, and they've elected several sixth year students to demonstrate how to do it properly. Everything seems to be going perfectly until two figures rise upon the platform: Hogwarts' most competitive couple.*Part of my Harry Potter AU series. It's recommended to go back and read through the rest, but not required.*





	Stronger than any Spell

**Author's Note:**

> Oiwake Takuro is the coach for Date Tech in canon

It was about mid-term at Hogwarts, and all the second years were gathered in the Great Hall for a special demonstration. All the tables had been removed and instead a long narrow stage stretched through the middle. The students were chatting excitedly until Defense against the Dark Arts professor Oiwake Takuro hopped up onto the stage, and a hush fell over the crowd.

“Alright you lot. It’s about that time when you all learn the basics of Wizard Dueling. This isn’t something to mess around with, and I don’t want to find you rug rats shooting nasty hexes at each other as a result. Dueling is a serious business and could result in doing permanent damage. So, if you don’t want to end up in St. Mungos, I suggest you pay close attention.”

He took a moment to observe the students, and once he was satisfied that he had their rapt attention, he continued.

“We got several sixth-year students to give a demonstration. Every one of them were taken from different houses and have each shown a talent for this sort of thing. First up we’ll have Hanamaki from Slytherin against Matsukawa from Ravenclaw.”

From each end of the stage the two adversaries climbed, giving each other a smirk once they were in position. They gave each other a polite bow and then readjusted their bodies to spring into action. The second years stared and held their breath, waiting for one of the boys to make the first move.

“ _Impedimenta_!” Hanamaki shouted and whipped his wand towards Matsukawa.

“ _Protego_ ,” Matsukawa replied immediately and the flash of light from Hanamaki’s wand ricocheted off an invisible force field a couple inches from Matsukawa’s face. Hanamaki drew a deep breath to spout another spell when Matsukawa gave another swish of his wand.

“ _Tarantallegra_.”

The crowd of second years burst into laughter as Hanamaki’s legs began carrying him around the stage in an exuberant dance, his face torn between frustration and amusement.

Professor Oiwake shooed them off the stage and brought on the next two adversaries: Kai from Hufflepuff and Yaku from Gryffindor. Despite the two being friends for a long time, neither let up an inch as they uttered their incantations. Kai was calm and steady, but he began to sweat at the hungry look in Yaku’s eyes as he blocked every spell Kai sent with a flourish. At last Yaku was able to stun Kai before the other could release his shield charm, and the Gryffindors in the crowd let out a cheer for their upperclassman.

“Alright, well done, you two. Next we have Sawamura from Hufflepuff against Kuroo from Ravenclaw.”

More whispers erupted in the crowd as they watched the two step up onto the platform. They were all wildly curious how the two would fair against each other since it was no secret that they were dating. That never stopped them from competing in Quidditch, but this was a duel with no teammates to take the pressure off. The tension in the room was palpable as the crowd hushed, watching as the two bowed politely. Kuroo’s face held his usual grin, his eyes sparkling with mischief. Sawamura was calm and focused and not about to let his boyfriend trip up his confidence.

“ _Expelliarmus_!” Daichi shouted as he sent the disarming spell toward Kuroo who simply flourished his wand. The spell bounced off an invisible shield without any incantation spoken out loud. Daichi’s eyes widened in surprise and the crowd gasped at the level of difficulty that required. Kuroo didn’t retaliate right away, taking a moment to savor the stunned look on his boyfriend’s face. He reacted instantly when Daichi moved his wand closer to try again, and this time he didn’t bother with a silent spell.

“ _Petrificus Totalus_!” Kuroo shouted, but his spell bounced off Daichi as well and he smirked back at Kuroo. A roar of chatter and cheers erupted from all the students, completely drawn into the famously competitive duo. While Kuroo was still shocked, Daichi shot an unspoken spell at him but he blocked it soundlessly once again. Their eyes were blazing as they retaliated against one another, just barely blocking each spell that came their way. Oiwake watched the two from below, wondering if he should put a stop to the nonverbal spells since the whole point was to teach the second years how to duel. They couldn’t learn much if they didn’t even know what spells they were using.

Daichi clenched his teeth as he fought hard to trip Kuroo up, but the other boy was wily and could typically read Daichi like an open book. He blocked a spell just in time, but he felt his shield charm weakening as he grew more distracted. He knew better than to lose focus, but a fleeting thought passed through his mind just as he released his next spell to Kuroo. At the same moment Kuroo sent one his way, impatient to finish the duel to his advantage. The spells collided midway, a burst of light bursting from the point and ricocheting right back into the two duelists. The force sent them both onto their backs and knocked them out for a brief moment.

Daichi awoke with a gasp and saw Oiwake’s face looking down at him.

“You alright, Kiddo?”

Daichi nodded and grimaced as he tried to sit up, his head pounding like an exuberant conga drum.

“Yeah, I think so.” Daichi stopped at the sound of his voice, which came out slightly higher and slyer than he was used to. He glanced around and saw he was still on the stage in the Great Hall, though he seemed to be on the other end of the platform. His vision was also partially hindered by some black hair spilling over his right eye. He swiped it aside and gasped when he saw the size of his hand. His fingers were longer than usual, as was his entire arm. His heart was beginning to pick up speed as he gazed across the long platform and locked eyes with himself, looking equally shocked.

“What’s wrong, you feel sick?” Oiwake asked next to him.

“Oiwake sensei… you’re not going to believe this.”

Both boys were immediately sent to Madame Saeko in the nursing unit to be checked out, and to ascertain if the boys were playing a prank on everyone else. If it had been just Kuroo, most of the staff would have rolled their eyes. But Sawamura was never one to behave so immaturely, even if he had a tendency to get hyped up in his thirst for competition.

As they walked down the hall, Ukai, who volunteered to escort the two, observed the way they were struggling to move in each other’s bodies. Kuroo’s body kept tripping over his feet and letting his arms flail as he walked, fascinated by the length of his limbs. Daichi’s face was screwed up in frustration as he tried to stretch his stride out as far as he could. If the situation wasn’t so dire, Ukai might have laughed at their comical body language, but he had never heard of a case like it before and worried they might not be able to switch them back.

Saeko cackled with glee when Ukai told her what happened and had them both sit down on a couple of beds while she examined them.

“There doesn’t seem to be anything else wrong with them physically, so I’m not sure what else I can do? Maybe Takeda sensei might be a better resource?”

Luckily the professor rushed into the infirmary, which was no surprise considering how quickly news spread in the castle.

“Is it true? You both switched bodies?!”

The two boys nodded solemnly.

“At least they switched with their boyfriend. Imagine how awkward it would be if they weren’t dating,” Saeko offered and Takeda sent her a glare. “What? I mean when they gotta pee they’re gonna have to--”

“Ahh, it’s not the same thing!” Kuroo cried in Daichi’s voice, covering his blushing face. “We don’t help each other pee, ugghh.”

“Relax, Kuroo. We just need to suck it up until we can switch back,” Kuroo’s body said with resigned practicality, a tone usually spoken by Daichi.

“And if we can’t?”

“I’m definitely gonna get a haircut. I can’t live like this.”

“Wait a minute,” Takeda interrupted before Daichi’s body could tackle Kuroo’s. “You were both utilizing unspoken spells, correct? Which ones were you using at the time of the collision?”

“It’s hard to say, we were using so many,” Daichi’s body said, and it unnerved Takeda hearing Kuroo’s nonchalant tone in Daichi’s voice.

“I think my focus was slipping,” Daichi admitted, and they all turned to him as he leaned Kuroo’s head back against the bedframe. “I was planning on sending a simple disarming spell, but at the last second I thought _I can take him_ , or something like that.”

Daichi’s eyes widened and gasped.

“I thought the same thing!”

The professors groaned while Saeko rolled her eyes.

“You two are sixth years! You should know better than to lose focus like that, you idiots,” Ukai growled and Takeda nodded his agreement.

“Alright, I’m going to research this further and see if we can come up with a solution. For now, just try to make do and attend classes like normal. I’ll make sure the entire staff knows of the switch… hopefully they believe me. Just one more thing,” He said in a sharp tone rarely used by the easy-going professor. “Do not, under any circumstances, go into your Animagus forms.”

“What? Why not?” Kuroo asked from Daichi’s body.

“Because your bodies have adapted to changing into that specific form, but the form itself is tied to your spirit. As far as I know, this situation is unprecedented, and we have no idea how that would affect everything else. Having an Animagus form is dangerous enough, adding this disaster into the mix, who knows what would happen?”

Both boys nodded, not eager to test fate and mess their bodies up even more than they had. Takeda dismissed them while he worked on a solution, and together they snuck off to the Room of Requirement, their own secret spot they discovered last year where they could get a little privacy from their nosy classmates. Kuroo shook his head as he gazed around the room, amazed at how everything seemed so much bigger from his new perspective.

“I can’t believe this is happening. I mean, Saeko-san was right, I’m glad I’m in your body and not anyone else’s.”

“That’s true, but I hope it gets fixed soon.”

Kuroo turned around and gave him a wicked grin, and it churned Daichi’s stomach seeing his own face look that sinister.

“Daichi,” He cooed as he moved back towards the sofa. “You wanna fool around with your own body?”

Daichi glowered at him and folded his arms in front of him.

“Why would I ever want to do that?”

“Because it’s kinda kinky? Or maybe you’d like to watch me do a little exploring.”

Daichi’s jaw dropped open as he watched his own body lounge on the sofa, loosening his yellow and black tie and sliding it off slowly. He gulped as he watched himself drop the tie next to him and pull his V-neck sweater over his head.

“Tetsu, what the hell are you doing?” He hissed as he stomped toward the sofa, which he did very quickly with his new, long stride.

Kuroo chuckled darkly, sending shivers down his spine.

“It’s weird seeing myself so uptight. Come on, who would ever have a chance like this?”

Daichi released a long breath. He had to admit it sounded like fun, but it bugged him that Kuroo wasn’t more worried about being stuck as him forever. He suddenly felt the urge to wipe that smug look off his own face. He stuck his chin out and slid onto the sofa, one leg on either side of Kuroo and began running his hands down his chest. It was strange to be touching his own body and didn’t find the same enjoyment out of touching Kuroo’s, but seeing his eyes widen and a light flush spread across his cheeks gave him a thrill of pleasure.

“Perhaps you’re right,” He said, letting his fingers graze across Kuroo’s cheek (or his cheek?). “Maybe this will add a whole new level to our relationship, especially when I know things about this body that you don’t.” He let his hand slide down to Kuroo’s side and pressed a finger in one certain spot. Kuroo let out a shriek and lurched to the side, but Daichi held him down as he laughed in Kuroo’s voice.

“Oh yeah? Well two can play at this game.” Kuroo snuck his hands behind his thighs and grazed them across, and Daichi immediately felt the effects. It half tickled, half made his body heat up in a dangerous way.

“Whoa, I’m gonna have to remember that one.”

Daichi watched as his face grinned even wider and leaned up towards him.

“Yeah? I look forward to it.”

Kuroo reached his hands up to cradle his face and pull him lower for a kiss, but Daichi scrunched up his face and shook it in disgust.

“No, I can’t. I can’t kiss my own face, it’s too weird.”

Kuroo laughed and buried his face into Daichi’s chest.

“This is weird I have to admit.”

“Aren’t you worried we won’t be able to switch back?”

“Yeah, I’m worried. But there’s nothing we can do about it right now, right?” Kuroo lifted his face to give him an impish look (still very strange seeing on his own face) and grabbed hold of his waist and flipped him onto his back on the sofa. Daichi took a moment to gaze at his body sprawled over it, his limbs barely fitting when usually he could rest quite comfortably on that sofa. His attention was hijacked as his boyfriend began to crawl over him, his body heating up the closer he moved towards his face. He gulped when Kuroo hovered right above him, and he tried to picture Kuroo’s face there instead of his own, but it was useless. It was like he was about to kiss a mirror. Kuroo snorted, and Daichi felt his face grow hot wondering what kind of an expression he was wearing. Then Kuroo’s mirth turned into something softer as he stroked the side of Daichi’s face.

“I know it’s you in there. You could be stuck in a gargoyle, and I’d still love you.”

Before Daichi could respond, Kuroo covered his eyes so he couldn’t see and immediately he felt soft lips on his. He sighed and wrapped his arms around his boyfriend and pulled him in closer. He was right, the lips might have been his, but the movement and spirit of it was still Kuroo. It would be sad if they could never use their Animagus forms again, but he could deal with looking like the most beautiful person he’s ever met.

 _You’re perfect,_ ” Daichi thought and suddenly there was a pulse of light from the contact of their lips. Daichi felt like he’d lost consciousness for a minute, and when he opened his eyes he experienced a wave of nausea at being in the opposite position he was a moment ago.

“Ugh, what happened?” Kuroo asked underneath him as he rubbed his face.

“I don’t know, I think-- Tetsu, we’re back.”

Kuroo’s hands slid down to reveal his eyes and they immediately widened as they took in Daichi’s face. After his initial surprise, he groaned in disappointment.

“Maaaaan, I was hoping to do dirtier things with you. You were just getting into it.”

Daichi laughed and punched him lightly in the side.

“You idiot, you should be grateful we switched back so quickly. Now I’m not going to be afraid of going to the bathroom.”

“Ah, you’re right. I at least wanted to shower as you, though.”

Daichi rolled his eyes and hovered over Kuroo’s face.

“You might not get to shower as me but showering _with_ me is always a possibility… in the future.”

Kuroo’s eyebrows shot up, his grin spreading so wide Daichi thought it was going to fall off his face.

“How far into the future?”

“Probably not as soon as you’d like.”

“Well, at least the possibility is there. I love possibilities! Hey, how did we switch back anyways? We weren’t doing any spells.”

“I don’t know, I was thinking something, and it just happened?”

“What were you thinking?!”

Daichi’s heart began to pound, and he contemplated the possibility of outrunning his long-legged boyfriend. Kuroo tightened his grip around his waist, his eyes narrowing under his eyelids as he waited for Daichi’s answer.

“Nothing special, just something about you.”

“What about me, Daichi?”

“Mmmur purfct.”

“What?”

Daichi groaned and squeezed his eyes shut. “You’re perfect, that’s what I thought. Now let me die in peace,” He grumbled as he buried his head in Kuroo’s chest. Underneath him Kuroo began to laugh, and Daichi felt warm as he felt him kiss the top of his head.

“I thought the same thing about you, Stupid. That’s why we switched back.”

Daichi frowned and lifted his head.

“But it wasn’t a spell.”

“Neither was the first time. Magic doesn’t have to be a spell you know, that’s why so much weird shit happens when you’re a kid before you even get to Hogwarts.”

“Well, we better go find Takeda sensei and let him know we’re back.”

“Wait-- do we have to? We could pretend to be each other for a while just to have some fun.”

Daichi snorted. “There’s no way I could duplicate that smile of yours.”

“You’re right, and I can only look constipated for so long.”

Kuroo realized his mistake too late, being trapped underneath his boyfriend and unable to escape his strong hands as Daichi went after every weak spot he had. When Daichi had finally untangled himself from Kuroo, they both left their safe haven to seek out Takeda, so he didn’t spend all night researching for their sakes. It ended up taking forever, unfortunately, since they were stopped every two feet by other students asking a million questions and poking their bodies as if that would help explain what had happened.

“Kuroo!!” Bokuto shouted as he charged through the crowd. When he finally reached the pair, he gripped onto Daichi’s face and pulled him close with his eyes blazing. “Kuroo! Are you in there?! Speak to me!”

Bokuto winced as Kuroo’s fist came down roughly on the top of his head.

“Let him go, you idiot. We switched back. And why would you scream in my face anyways, who does that?”

“But you were lost in Sawamura’s body! I thought my voice could bring you back.”

Kuroo’s mouth dropped open and stood still for a while, but eventually he just shook his head.

“I don’t even wanna touch that. He’s beyond my help.”

When they finally entered Takeda’s office, all they could see was a mountain of ancient texts piled up on his desk and the sound of pages turning wildly.

“Uh, Sensei?” Kuroo asked tentatively and Takeda’s head popped up above the stacks.

“Ah! Are you boys okay? Any weird symptoms I should know about?”

“Just that we’re already switched back.”

“Aw, already? Oh! I mean, that’s great boys,” He added quickly as he moved away from his desk and walked toward them, observing them closely.

“Sensei, don’t tell me you were hoping to do some experiments on us.”

“What? No-- well, maybe just a couple for posterity’s sake. Like I said the situation was entirely unprecedented. How did you do it?”

Kuroo winced and scratched the back of his head and Daichi let out a nervous cough.

“Um, well, we thought the same thing at the same time again.”

“Ahhhh,” Takeda mused as he tapped his finger to his chin. “I feel foolish for not suggesting it first, it should have been obvious. Wait, did you preemptively decide to think the same thing, or did it happen naturally?”

“We didn’t plan it ahead of time,” Daichi answered, hoping he didn’t ask what they were thinking. He was embarrassed enough.

“I see… so it’s possible it might not have worked unless it was unprompted. Well, in the meantime no more dueling with silent spells, and watch your thought process around each other. I’ll go ahead and announce that everything is back to normal but let me know when you switch again so I can take better notes in case it happens to anyone else.”

“Sensei, don’t you mean _if_?”

“Nonsense! With how close and competitive you two are, I’m sure that won’t be the last of your accidents!”

Daichi and Kuroo exchanged a nervous look. Takeda looked a little too excited about their potential magical hiccups for their taste, and as soon as they left his office decided for safety’s sake to try to have a more normal relationship.

 

**Author's Note:**

> Hogwarts is holding their yearling dueling club for the second years, and they've elected several sixth year students to demonstrate how to do it properly. Everything seems to be going perfectly until two figures rise upon the platform: Hogwarts' most competitive couple.


End file.
